Magnetic resonance imaging apparatus and method

Abstract

A magnetic resonance imaging apparatus includes a movement unit which moves a subject placed in a static magnetic field, a collector which collects data corresponding to a magnetic resonance signal emitted from the subject, a detector which detects a position of a particular section of the subject in the static magnetic field, a reconstruction unit which reconstructs an image, based on the collected data, when the detected position falls within an allowable area, and a controller which controls the movement unit to compensate for a deviation of the detected position from a reference position.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2006-004019, filed Jan. 11, 2006, the entire contents of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a magnetic resonance imaging (MRI) apparatus and method for performing image reconstruction, using data collected when a body portion, such as the diaphragm, is positioned in a preset allowable area.[0004]2. Description of the Related Art[0005]The heart, for example, moves in accordance with, for example, breathing. As an imaging method employed to perform imaging of such a moving target section, there is a known movement compensation method in which data collected when the target section is positioned within a preset allowable area is utilized for reconstructing the target section. In the movement compensation method, a magnetic resonanc...

AI Technical Summary

Benefits of technology

"The present invention provides a magnetic resonance imaging apparatus and method that can compensate for variations in the position of a target section in a static magnetic field, while ensuring high-quality imaging. This is achieved by detecting the position of the target section and reconstructing an image based on the collected data, within an allowable area. The detected position can be set based on a range of variations in the position within a unit period, and the movement unit can be controlled to compensate for any deviation of the detected position from a reference position. The technical effects of the invention include improved accuracy and precision in magnetic resonance imaging, particularly in cases where the subject is moving or positioned in a non-uniform magnetic field."

Problems solved by technology

However, when the movement compensation method is employed, not all data collected can be utilized for reconstruction, and the required imaging time is lengthened.

In this case, the position of a target section is greatly changed, and may fall outside an allowable area for a long time.

This further reduces the probability of employment of collected data for reconstruction, which further lengthens the required imaging period.

At worst, the target section may always fall outside the allowable area.

In this case, reconstruction cannot be realized, and hence the imaging operation cannot be finished.

In the above-described movement compensation method, however, the slicing position is moved in the static magnetic field during imaging, which means that the slicing position cannot be kept at a position at which the static magnetic field is uniform.

Accordingly, if the imaging method sensitive to static magnetic field uniformity is combined with the above-mentioned movement compensation method, the degree of suppression of the occurrence of fat tissue signals may be reduced, and a reduction in image quality, such as an increase in banding artifacts in the SSFP method, may be involved.

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